The present invention relates to DC motors, more particularly, although not limited thereto, DC motors for driving electric equipment such as, for example, copy machines, laser printers and/or storage medium drives for personal computers. The present invention is also applicable to DC motors for driving fans for cooling electronic equipment and for cooling heat sinks for cooling electric components. Further, the present invention relates to heat sink fans employing such DC motors.
In recent years, personal computers, have shifted to a notebook type from a laptop type and are required to have thinner design, and accordingly DC motors for the personal computers are required to be thinner. In conventional DC motors, a rotating member is supported by a stationary member through a pair of ball bearings which are axially spaced apart from each other. Therefore, the construction of the rotating member, the stationary member and the ball bearings limits the amount of reduction in the axial height of the motor, namely motor thinness. If a thinner motor design is achieved, then this motor can not only effectively be applied to storage medium drives of notebook type personal computers, but is also instrumental in minimizing the height of a heat sink fan to be mounted on a semiconductor device. In various uses of DC motors as mentioned above, a decrease in motor volume provides significant advantage as well.
However, stability of motor performance is not guaranteed if, for example, one of a pair of ball bearings is merely removed or eliminated to reduce the axial height of the motor.